‘Scare over miscarriage scans unjustified’

From the NHS Behind the headlines blog:

Several news sources have today reported that errors during early-pregnancy ultrasounds are leading to unnecessary abortions. The Daily Mail said that hundreds of babies a year may die due to ‘blunders’ in testing and the Metro said that unreliable tests caused a baby to die every day…

Despite what headlines have suggested, early pregnancy ultrasounds are invaluable and highly accurate diagnostic tools, and even using current guidelines, the vast majority of cases would be accurately diagnosed…

It should be noted that while the researchers did suggest there may be around 400 cases of misdiagnosis each year, there is no indication that the majority of them would be terminated, as newspapers have reported…

The news is based on four studies examining the use of ultrasound scanning to monitor early-stage pregnancies…

Press coverage of these studies tended to be quite alarming, with suggestions that 400 babies a year die or are terminated due to errors in testing. For example, the Metro ran front-page coverage saying that ‘a baby per day dies due to test error’, while the Daily Mail said that fears were ‘hundreds of healthy babies are being aborted every year simply because of scan blunders’.

However, this figure appears to be based on one research paper that estimated around 400 UK pregnancies may be misclassified as miscarriages, which does not necessarilly mean they are terminated.

At a press conference attended by reporters from a number of national newspapers, some of the study authors stated that there was no reliable source of evidence to confirm how often misclassified pregnancies would be terminated…

Also, many press stories were accompanied with pictures of late-stage ultrasound scans, showing clearly visible foetuses. This would suggest that doctors are performing terminations close to the natural end of pregnancy, when in fact these studies were concerned with diagnosis within the early stages of pregnancy, when an embryo might typically be around 5-6mm in length.